Boundary layer turbomachine

ABSTRACT

A boundary layer turbomachine can include a housing ( 10 ) defining an interior space and having an inlet opening and an outlet opening to facilitate movement of a fluid through the housing ( 10 ). The boundary layer turbomachine can also include a rotor assembly ( 20 ) disposed in the rotor chamber and configured to rotate about an axis of rotation ( 1 ). The rotor assembly ( 20 ) can have a plurality of disks ( 21 ) spaced apart along the axis of rotation ( 1 ) to provide gaps ( 54 ) between the disks ( 21 ). The plurality of disks ( 21 ) can also define an interior opening ( 26 ) along the axis of rotation ( 1 ). The rotor assembly ( 20 ) can have a disk carrier ( 46 ) disposed at least partially in the interior opening ( 26 ) in support of the plurality of disks ( 21 ). The disk carrier ( 46 ) can have a fluid passageway ( 47 ) exposed to two or more of the gaps ( 54 ) between the disks ( 21 ). The fluid can pass through gaps ( 54 ) between the disks ( 21 ) and the interior opening ( 26 ) as the fluid moves through the housing ( 10 ).

BACKGROUND

Transfer of motive force between stacked rotating disks and a fluid isdescribed by Tesla in U.S. Pat. Nos. 1,061,142 and 1,061,206. Accordingto these patents, fluid drags on closely spaced rotating disks due toviscosity and adhesion of a surface layer of the fluid, which subjectsthe fluid to two forces, one acting tangentially in the direction ofrotation and the other acting radially outward. The combined effect ofthese tangential and centrifugal forces is to propel the fluid withcontinuously increasing velocity in a spiral path until it reaches asuitable peripheral outlet from which it is ejected.

The design described by Tesla can be used as a pump or as a motor. Suchdevices take advantage of the properties of a fluid when in contact withthe rotating surfaces of the disks. If the disks are driven by thefluid, then as the fluid passes between the spaced apart disks, themovement of the fluid causes the disks to rotate thereby generatingpower which can be transmitted external to the device via a shaft toprovide motive force for various applications. Accordingly, such devicesfunction as a motor or turbine. On the other hand, if the fluid isessentially static, rotation of the disks will cause the fluid tocommence rotating in the same direction as the disks and to thus drawthe fluid through the device, thereby causing the device to function asa pump or a fan. In this disclosure, all such devices, whether used as amotor or as a pump or fan, are referred to generically as “boundarylayer turbomachines.”

Despite numerous improvements to the original design by Tesla, suchmachines have found limited practical application due to variousdrawbacks such as reliability and costs. A typical boundary layerturbomachine has several shortcomings. The thin disks of a typicalboundary layer turbomachine tend to deflect under operating loads, whichcan cause contact with other disks and/or other structures, such as ahousing that encloses the disks. To minimize this potentiallydestructive contact, some boundary layer turbomachines include featuressuch as dimples incorporated into the housing or through-bolts which actas spacers. In addition, efficiencies of typical boundary layerturbomachines can be limited. Accordingly, improvements in boundarylayer turbomachine design continue to be sought.

SUMMARY

A boundary layer turbomachine is disclosed herein that can minimize oreliminate disk deflections that tend to cause contact between adjacentdisks and/or a housing. In one aspect, principles are disclosed hereinthat also provide increased efficiency of the boundary layerturbomachine. The boundary layer turbomachine can include a housingdefining an interior space and having an inlet opening and an outletopening to facilitate movement of a fluid through the housing. Theboundary layer turbomachine can also include a rotor assembly disposedin the rotor chamber and configured to rotate about an axis of rotation.The rotor assembly can have a plurality of disks spaced apart along theaxis of rotation to provide gaps between the disks. The plurality ofdisks can also define an interior opening along the axis of rotation.The rotor assembly can have a disk carrier disposed at least partiallyin the interior opening in support of the plurality of disks. The diskcarrier can have a fluid passageway exposed to two or more of the gapsbetween the disks. The fluid can pass through gaps between the disks andthe interior opening as the fluid moves through the housing.

In one aspect, a rotor assembly for a boundary layer turbomachine isdisclosed. The rotor assembly can include a plurality of disks spacedapart along an axis of rotation to provide gaps between the disks. Theplurality of disks can define an interior opening along the axis ofrotation. The rotor assembly can also include a disk carrier disposed atleast partially in the interior opening in support of the plurality ofdisks. The disk carrier can have a fluid passageway exposed to at leasttwo of the gaps between the disks, such that fluid passes through the atleast two of the gaps between the disks and the interior opening as thefluid moves through the rotor assembly.

There has thus been outlined, rather broadly, the more importantfeatures of the invention so that the detailed description thereof thatfollows may be better understood, and so that the present contributionto the art may be better appreciated. Other features of the presentinvention will become clearer from the following detailed description ofthe invention, taken with the accompanying drawings and claims, or maybe learned by the practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a rotor assembly of a boundary layerturbomachine in accordance with an example of the present disclosure.

FIG. 1B is a side view of the rotor assembly of FIG. 1B.

FIG. 1C is a side cross-sectional view of the rotor assembly of FIG. 1A.

FIG. 1D is a cross-sectional view of a disk pack of the rotor assemblyof FIG. 1A.

FIGS. 1E and 1F illustrate a disk carrier 46 of the rotor assembly ofFIG. 1A.

FIGS. 1G and 1H illustrate an assembly of outer support disks and thedisk carrier of the rotor assembly of FIG. 1A.

FIG. 1I illustrates an assembly of disks on the disk carrier of therotor assembly of FIG. 1A.

FIG. 1J illustrates the outer support disks assembled on the diskcarrier of the rotor assembly of FIG. 1A.

FIGS. 1K and 1L illustrate aspects and features of a rotor assembly inaccordance with an example of the present disclosure.

FIGS. 1M-1T illustrate aspects and features of a rotor assembly having akeyed disk carrier in accordance with another example of the presentdisclosure.

FIG. 2 is a perspective view of a boundary layer turbomachine inaccordance with an example of the present disclosure.

FIGS. 3A and 3B are exploded views of the boundary layer turbomachine ofFIG. 2 .

FIG. 4A is a cross-sectional view of the boundary layer turbomachine ofFIG. 2 taken between housing portions with a rotor assembly omitted.

FIG. 4B is a cross-sectional view of the boundary layer turbomachine ofFIG. 2 taken between housing portions showing a rotor assembly.

FIG. 5 is a side view of a disk of a rotor assembly in accordance withan example of the present disclosure.

FIG. 6 is a detail view of disk peripheral edges of a rotor assemblyhaving a tapered zone in accordance with an example of the presentdisclosure.

FIG. 7 is a cross-sectional view of a portion of a rotor assembly inaccordance with an example of the present disclosure.

FIG. 8 is a cross-sectional view of a portion of a rotor assemblyshowing an optional helical baffle within the interior opening inaccordance with another example of the present disclosure.

FIGS. 9A and 9B illustrate a computer model showing the fluid volume inan interior space of a boundary layer turbomachine in accordance with anexample of the present disclosure.

FIGS. 10A and 10B illustrate a boundary layer turbomachine in accordancewith another example of the present disclosure.

FIGS. 11A and 11B illustrate a rotor assembly of the boundary layerturbomachine of FIGS. 10A and 10B.

FIG. 12 illustrates a rotor assembly of a boundary layer turbomachine inaccordance with another example of the present disclosure.

FIG. 13A is a perspective view of a boundary layer turbomachine inaccordance with another example of the present disclosure.

FIGS. 14A and 14B are partially exploded perspective views of theboundary layer turbomachine of FIG. 13 .

FIG. 15A is a cross-sectional view of the boundary layer turbomachine ofFIG. 13 parallel to a rotational axis.

FIG. 15B is a cross-sectional view of the boundary layer turbomachine ofFIG. 13 with a rotor assembly omitted.

FIG. 16 is a cross-sectional view of the boundary layer turbomachine ofFIG. 13 perpendicular to a rotational axis.

FIG. 17 is a detail of the cross-sectional view of the boundary layerturbomachine of FIG. 16 .

FIG. 18 is perspective view of a rotor assembly of the boundary layerturbomachine of FIG. 13 .

FIG. 19 illustrates a disk and spacers of the rotor assembly of theboundary layer turbomachine of FIG. 13 .

FIG. 20 is a perspective view of a boundary layer turbomachine inaccordance with another example of the present disclosure.

FIG. 21 is a cross-sectional view of the boundary layer turbomachine ofFIG. 20 .

FIG. 22A is a schematic illustration of a boundary layer turbomachinesconfigured as a pump in accordance with an example of the presentdisclosure.

FIG. 22B is a schematic illustration of a boundary layer turbomachinesconfigured as a vacuum pump in accordance with an example of the presentdisclosure.

FIG. 22C is a schematic illustration of a boundary layer turbomachinesconfigured as a fan or a blower in accordance with an example of thepresent disclosure.

FIG. 22D is a schematic illustration of a boundary layer turbomachinesconfigured as an in-line pump in accordance with an example of thepresent disclosure.

FIG. 22E is a schematic illustration of a boundary layer turbomachinesconfigured as a boat motor in accordance with an example of the presentdisclosure.

FIG. 22F is a schematic illustration of a boundary layer turbomachinesconfigured as a thruster in accordance with an example of the presentdisclosure.

FIGS. 23A-23C illustrate drag reducing structures for surfaces exposedto fluid flow, in accordance with several examples of the presentdisclosure.

These drawings are provided to illustrate various aspects of theinvention and are not intended to be limiting of the scope in terms ofdimensions, materials, configurations, arrangements or proportionsunless otherwise limited by the claims.

DETAILED DESCRIPTION

While these exemplary embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, it should beunderstood that other embodiments may be realized and that variouschanges to the invention may be made without departing from the spiritand scope of the present invention. Thus, the following more detaileddescription of the embodiments of the present invention is not intendedto limit the scope of the invention, as claimed, but is presented forpurposes of illustration only and not limitation to describe thefeatures and characteristics of the present invention, to set forth thebest mode of operation of the invention, and to sufficiently enable oneskilled in the art to practice the invention. Accordingly, the scope ofthe present invention is to be defined solely by the appended claims.

Definitions

In describing and claiming the present invention, the followingterminology will be used.

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise. Thus, for example, reference to“a disk” includes reference to one or more of such disks and referenceto “the spacer” refers to one or more of such spacers.

As used herein with respect to an identified property or circumstance,“substantially” refers to a degree of deviation that is sufficientlysmall so as to not measurably detract from the identified property orcircumstance. The exact degree of deviation allowable may in some casesdepend on the specific context.

As used herein, “adjacent” refers to the proximity of two structures orelements. Particularly, elements that are identified as being “adjacent”may be either abutting or connected. Such elements may also be near orclose to each other without necessarily contacting each other. The exactdegree of proximity may in some cases depend on the specific context.

As used herein, “boundary layer thickness” refers to a distance from asolid surface at which the viscous flow velocity is 99% of a freestreamvelocity. Most often, the turbomachine can be operated undersubstantially laminar conditions, although the device can sometimes befunctional under turbulent conditions.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary.

As used herein, the term “at least one of” is intended to be synonymouswith “one or more of” For example, “at least one of A, B and C”explicitly includes only A, only B, only C, or combinations of each.

As used herein, the term “about” is used to provide flexibility andallow for imprecision associated with a given term, metric or value. Thedegree of flexibility for a particular variable can be readilydetermined by one skilled in the art. However, unless otherwiseenunciated, the term “about” generally connotes flexibility of less than5%, and most often less than 1%, and in some cases less than 0.01%.

Numerical data may be presented herein in a range format. It is to beunderstood that such range format is used merely for convenience andbrevity and should be interpreted flexibly to include not only thenumerical values explicitly recited as the limits of the range, but alsoto include all the individual numerical values or sub-ranges encompassedwithin that range as if each numerical value and sub-range is explicitlyrecited. For example, a numerical range of about 1 to about 4.5 shouldbe interpreted to include not only the explicitly recited limits of 1 toabout 4.5, but also to include individual numerals such as 2, 3, 4, andsub-ranges such as 1 to 3, 2 to 4, etc. The same principle applies toranges reciting only one numerical value, such as “less than about 4.5,”which should be interpreted to include all of the above-recited valuesand ranges. Further, such an interpretation should apply regardless ofthe breadth of the range or the characteristic being described.

Any steps recited in any method or process claims may be executed in anyorder and are not limited to the order presented in the claims.Means-plus-function or step-plus-function limitations will only beemployed where for a specific claim limitation all of the followingconditions are present in that limitation: a) “means for” or “step for”is expressly recited; and b) a corresponding function is expresslyrecited. The structure, material or acts that support the means-plusfunction are expressly recited in the description herein. Accordingly,the scope of the invention should be determined solely by the appendedclaims and their legal equivalents, rather than by the descriptions andexamples given herein.

Boundary Layer Turbomachine

With reference to FIGS. 1A-1J, aspects and features of a rotor assembly20 are illustrated in accordance with an example of the presentdisclosure. The complete rotor assembly 20 is shown in perspective andside views in FIGS. 1A and 1B, respectively. The rotor assembly 20 caninclude a plurality of disks 21 oriented about a disk carrier 46. Outersupport disks 57 a, 57 b can be disposed about opposite ends of theplurality of disks 21. The outer support disks 57 a, 57 b can be used to“cap” ends of the disks 21, thus providing smooth exposed disk faces onopposite ends of a disk pack or assembly. A side cross-sectional view ofthe rotor assembly 20 is shown in FIG. 1C. A cross-section of the diskpack or assembly, including the disks 21 and the outer support disks 57a, 57 b, is shown isolated from the disk carrier in FIG. 1D. The diskcarrier 46 is shown isolated in FIGS. 1E and 1F. The outer support disks57 a, 57 b and the disk carrier 46 are shown in FIGS. 1G and 1H. Thus,the plurality of disks 21 and outer support disks 57 a, 57 b areparallel to one another and are oriented about a common rotational axis.Typically, the plurality of disks and outer support disks are circularand have a common outer diameter.

The disk carrier 46 can include a disk portion 83 and extension portions22 a, 22 b as illustrated in FIG. 1C. The extension portions 22 a, 22 bcan be configured to couple the rotor assembly 20 to a portion of aturbomachine as disclosed herein (e.g., a housing 10 shown in phantomlines in FIG. 1C) and facilitate rotation of the rotor assembly 20 aboutan axis of rotation 1. For example, the extension portions 22 a, 22 bcan extend in opposite directions from the plurality of disks 21 and canbe substantially inline to facilitate rotation of the rotor assemblyabout the axis 1. The extension portions 22 a, 22 b can be mounted onbearings when coupled to the housing 10 to provide a low frictionrotational interface. In one alternative, the bearings can comprisebrush bearing seals although other rotational interfaces can be used.

With particular reference to FIGS. 1C and 1D, the plurality of disks 21can be spaced apart along the axis of rotation 1 to provide gaps 54between the disks. In one aspect, the disks can be substantially planarand oriented perpendicular to the axis of rotation, although anysuitable disk configuration can be utilized, such as a conical diskconfiguration or other dimensions and configurations as outlined furtherbelow in connection with any one of the embodiments described herein.For example, non-planar disks can be nested to form a rotor assemblyusing the principles described herein. Regardless, outer surfaces ofadjacent disks 21 can be substantially parallel to one anotherthroughout. Furthermore, any suitable number of disks can be utilized(e.g., depending on power requirements), although typically more thanfive and most often more than ten disks are utilized. The plurality ofdisks 21 can define an interior opening 26 (radially internal to theplurality of disks 21) along the axis of rotation 1.

As shown in FIG. 1C, the disk carrier 46 can be disposed at leastpartially in the interior opening 26 in support of the plurality ofdisks 21. For example, the disks 21 (e.g., individual disks or in groupsof two or more) can be slid or otherwise positioned over the diskportion 83 of the disk carrier 46. The disks can generally have an inneropening diameter which is about equal to an outer diameter of the diskcarrier. This can allow the disks to be merely contacting the diskcarrier and friction fit together. Alternatively, the inner perimeter ofeach disk can be secured to an outer surface of the disk carrier (e.g.gluing, welding, notches, etc).

The disks can be positioned about the disk carrier 46 such that one ormore fluid passageways 47 of the disk carrier 46 can be exposed to twoor more of the gaps 54 between the disks 21. These fluid passageways 47can be openings along the disk carrier. In other words, one or morefluid passageways 47 can overlap or traverse two or more of the gaps 54between the disks 21 such that the fluid passageways 47 and the multiplegaps 54 are in fluid communication. Thus, fluid can pass through thegaps 54 between the disks 21 and the interior opening 26 as the fluidmoves through the rotor assembly 20. The outer support disks 57 a, 57 bcan be located outside or in a non-overlapping relationship with theinner fluid passageways 47. The disks 21 are omitted to reveal the innerfluid passageways 47 in FIG. 1G. Any suitable number of fluidpassageways 47 can be included. In one aspect, the disk carrier 46 caninclude at least three fluid passageways. The fluid passageways 47 canhave any suitable configuration, individually or collectively. In oneaspect, the fluid passageways 47 can be distributed (uniformly ornon-uniformly) circumferentially about the disk carrier 46. In oneexample, the fluid passageways 47 can comprise elongated slots extendinglongitudinally along the rotation axis 1 of the disk carrier 46.However, the fluid passageways can be circular, rectangular,overlapping, etc. Typically, the fluid passageways 47 can extend adistance corresponding to a width of the plurality of disks 21. In thismanner, each of the gaps 54 is fluidly connected to the interior opening26 via the fluid passageways 47. As a general rule, the fluidpassageways 47 can comprise from about 20% to about 95% of an externalarea of the disk portion 83, and generally from about 50% to 90%. Thefluid passageways can generally have any shape or size as long asstructural integrity of the disk carrier is maintained over expectedoperating conditions.

With fluid entering the disk carrier 46 (e.g., via the fluid passageways47), the disk carrier 46 can include a central chamber 49, which canserve as a conduit for fluid to move through the disk carrier 46. In oneaspect, the extension portions 22 a, 22 b can also facilitate movementof fluid through the disk carrier 46. For example, the extensionportions 22 a, 22 b can include vent ports 25 a, 25 b extending throughthe respective extension portions in fluid communication with thecentral chamber 49 of the disk carrier 46 (i.e., in fluid communicationwith the interior opening 26). In addition, the extension portions 22 a,22 b can include outer fluid passageways 48 a, 48 b in fluidcommunication with the vent ports 25 a, 25 b, respectively. Thus, fluidcan exit the housing 10 via the disk carrier 46 by passing through theinner fluid passageways 47, the central chamber 49, the vent ports 25 a,25 b, and the outer fluid passageways 48 a, 48 b. In this manner, fluidexits the disk carrier 46 off axis through fluid passageways 48 a, 48 b.Fluid can also enter the housing 10 in the reverse direction throughthese openings in the disk carrier 46 when operated as a pump or fan.The disk carrier 46 can therefore facilitate the exhaust of fluids from,or the inlet of fluids into, the housing 10 of a turbomachine. The innerfluid passageways 47, the central chamber 49, the vent ports 25 a, 25 b,and the outer fluid passageways 48 a, 48 b of the disk carrier 46 canhave any suitable configuration providing that there is sufficient areato allow for fluid (in a liquid and/or gaseous state) to pass throughwithout undue restriction while maintaining the structural integrity ofthe disk carrier 46.

In one aspect, the extension portion 22 a, 22 b can facilitate couplingthe rotor assembly 20 to a generator or a motor. For example, theextension portion 22 a, 22 b can include interface features or surfaces24 a, 24 b to interface with, and facilitate coupling to, a drivecomponent such as a generator or a motor. The interface features 24 a,24 b can have any suitable configuration in accordance with theseobjectives. In one aspect, a generator (e.g., an electric generator or apump) can be coupled to the rotor assembly 20 to generate power as thefluid moves through the rotor assembly 20. In another aspect, a motorcan be coupled to the rotor assembly 20 to cause rotation of the rotorassembly, thereby causing movement of the fluid through the rotorassembly 20 and utilizing a boundary layer turbomachine as a pump. Theextension portion 22 a, 22 b can therefore serve as a mechanicaltransfer coupling for the rotor assembly 20 to an external device, suchas a generator or a motor. Any suitable generator or motor can beutilized with the boundary layer turbomachines described herein, as longas such components are properly designed and sized as with other typesof pumps or turbines.

The disk carrier 46 can provide benefits in balancing the disks 21 uponassembly. For example, an outer surface 93 of the disk portion 83 of thedisk carrier 46 can be configured to interface with inner radialsurfaces of the disks 21 and outer support disks 57 a, 57 b. The outersurface 93 can therefore serve as a locating feature for the disks ofthe disk pack, which can maintain consistency of assembly and reducevariation in location among the disks relative to the rotational axis 1.Thus, the disk carrier 46 can improve the degree and ease of balancingthe disks 21, which is beneficial in operation particularly as theturbomachine increases in rpm, and during the initial startup where thetorque is very low at low rpm.

Although the various components of the rotor assembly 20 can beconstructed of any suitable material, in one aspect the rotor assembly20 (e.g., the disks 21 and/or the disk carrier 46) can be made in wholeor in part from a composite material, such as carbon fiber composite(e.g., Toray T800S), basalt fiber composite, or any other suitablelightweight structural material. In one example, the disks 21 can beformed of a woven fiber composite material (e.g. warp/weft). In oneembodiment, the woven fiber material can be a basalt fiber material suchas, but not limited to, commercially available 15582/50 material. Inanother example, the disks 21 can be formed of a ceramic compositematerial, which may be advantageous for high temperature applications.In one aspect, the disk carrier 46 can be made of a metal, such asaluminum, stainless steel, and/or titanium, a ceramic, a carbon fibercomposite, or the like. As a general guideline, the rotor assembly 20can be designed to provide a low mass to surface area ratio. Typically,a lower mass to surface area ratio provides improved performance as longas sufficient strength is maintained in the rotor assembly 20. In somecases, the rotor assembly 20 can be provided as a complete unit as areplacement of a damaged or worn rotor assembly.

FIG. 1I shows assembly of the disks 21 on the disk carrier 46 and FIG.1J shows the outer support disks assembled on the disk carrier. Thedisks 21 can be secured to one another and the outer support disks 57 a,57 b with one or more fasteners or rods. Furthermore, as discussed inmore detail in connection with a related variation, spacers can beoptionally used to maintain a uniform gap distance between adjacentdisks. These spacers can have various shapes and can be fixed viapermanent means or via through-holes which extend through the pluralityof disks (e.g. FIG. 1I). Notably, these rotor assemblies 20 whichinclude a disk carrier can also be used in connection with any of theconfigurations illustrated and described in more detail with respect toFIGS. 2-23C.

With reference to FIGS. 1K and 1L, aspects and features of a rotorassembly 20′ are illustrated in accordance with another example of thepresent disclosure. The plurality of disks identified by referencenumber 21 above have been omitted from these figures for clarity. Inthis case, a disk carrier 46′ can be configured to couple any of thevarious disks of a rotor assembly. This can ease assembly and providetorque transfer directly between a given rotor assembly disk and thedisk carrier 46′. For example, the disk carrier 46′ can include a diskcoupling interface portion 61, and one or more of the rotor assemblydisks can have a carrier coupling interface portion. Such a carriercoupling interface portion is shown in FIG. 1L, as an example, byreference number 63 on outer support disks 57 a′, 57 b′. An innersupport disk 57 c can be included between disks 21 discussed above toprovide additional support for the disks 21. The outer and inner supportdisks are utilized to couple with and provide support for the pluralityof disks 21 (discussed above) in the rotor assembly. In one embodiment,the inner support disk 57 c can be integrally formed with the diskcarrier 46′ (e.g., fixedly coupled to one another, such as by welding).In a particular aspect of this embodiment, a portion of the innersupport disk 57 c can partition a central chamber within the diskcarrier 46′ by extending through the disk carrier 46′, thus blocking orobstructing the central chamber local to the mid-span support. In thiscase, fluid is prevented from passing entirely through the disk carrier,as the central opening has been separated and subdivided by the innersupport disk 57 c. Alternatively, the inner support disk 57 c caninclude a central aperture that forms a portion of a central chamberthus allowing fluid to pass entirely through the disk carrier 46′. Inother embodiments, the inner support disk 57 c can include a carriercoupling interface portion that is the same or different from a carriercoupling interface portion included in the outer support disks 57 a′, 57b′. The disk coupling interface portion 61 and the carrier couplinginterface portion(s) 63 can interface to couple the disk carrier and therotor assembly disks to one another. In one embodiment, all of the rotorassembly disks will have carrier coupling interface portions, althoughany combination of rotor assembly disks can have carrier couplinginterface portions.

As shown in FIGS. 1K and 1L, the disk coupling interface portion 61 ofthe disk carrier can comprise protrusions 61 a that extend radiallyoutward relative to the axis of rotation 1. On the other hand, the rotorassembly disks (e.g., outer support disks 57 a′, 57 b′ of FIG. 1L) canhave protrusions 63 a that extend radially inward toward the axis ofrotation 1. Thus, the disk coupling interface portion 61 and the carriercoupling interface portion 63 can comprise complementary protrusions 61a, 63 a that, when coupled, are circumferentially offset from oneanother about the axis of rotation 1. The outer support disks 57 a′, 57b′ are configured to be disposed at outer ends of the plurality of disks21, and the inner support disk 57 c is configured to be disposed betweenat least two of the plurality of disks. Thus, the various disks of therotor assembly can be directly coupled to the disk carrier 46′ in amanner to transfer torque between the components about the axis ofrotation 1. In other words, the coupling interfaces provided by thecoupling interface portions 61, 63 can facilitate coupling to oneanother to prevent relative movement in a rotational degree of freedomabout the axis of rotation 1.

It should be recognized that the coupling interface portions 61, 63 canhave any suitable configuration. For example, the complementaryprotrusions 61 a, 63 a can be of any suitable configuration to form arotationally fixed interface between the disks (e.g., the outer supportdisks, 57 a, 57 b, the inner support disk 57 c, and/or the disks 21) andthe corresponding coupling interface portion on the disk carrier 46′. Inone embodiment, the protrusions 61 a, 63 a can be splines of anysuitable configuration, such as castellated profile splines or any othersuitable spline profile or shape. The coupling interface portions 61, 63can have any suitable type of fit with one another. For example, thecomplementary protrusions 61 a, 63 a of the coupling interface portions61, 63 can be sized for a clearance fit, a transition fit, or aninterference fit. The geometry of the complementary protrusions 61 a, 63a can provide a mechanical resistance to relative rotation between thecoupling interface portions 61, 63 about the axis of rotation 1 that issufficient to prevent such relative rotation. As a result, the diskcarrier 46′, disks 21, and support disks 57 a,57 b,57 c can rotatetogether as a single unit. In one aspect, the protrusions 61 a, 63 a canextend parallel to the axis of rotation 1 (as illustrated in FIGS. 1Kand 1L) or may extend helically about the axis of rotation 1. In anotheraspect, the protrusions 61 a, 63 a can extend in the radial directionfrom a cylindrical base shape (as illustrated in FIGS. 1K and 1L) or aconical base shape (i.e., tapering along the axis of rotation 1). In afurther aspect, radial heights of the protrusions 61 a, 63 a can beconstant or variable (e.g., tapering in height) along the axis ofrotation 1. In addition, a weld or adhesive can be applied at theinterface of the protrusions 61 a, 63 a to fix the coupling interfaceportions 61, 63 to one another.

With further reference to FIGS. 1K and 1L, fluid passageways 47′ of thedisk carrier 46′ can be defined at least in part by spans 79 in the diskportion 83′ extending along the axis of rotation 1. As illustrated, thespans 79 can extend parallel to the axis of rotation 1, although otherconfigurations are contemplated, such as extending helically about theaxis of rotation 1. As shown in the figures, the disk coupling interfaceportion 61 can be associated with the spans 79, and in some cases can becommensurate in longitudinal length. In one aspect, the spans 79 can beintegrated with the coupling interface portion 61, such as forming atleast a part of the protrusions 61 a and/or a recess between adjacentprotrusions configured to receive an interfacing protrusion 63 a of adisk. Integrating the interlocking coupling interface portion 61 withthe spans 79 can improve disk alignment and maximize the fluid exit areaof the fluid passageways 47′ to and from the inner chamber. The innersupport disk 57 c can be positioned anywhere along the spans 79. Thus,in this embodiment, the inner support disk 57 c can provide mid-spansupport for the spans 79. In contrast, the outer support disks 57 a′, 57b′ in the illustrated example are configured to abut ends of the diskcoupling interface portion 61 proximate the outer ends of the spans 79,thus limiting their position to ends of the disk portion 83′ of the diskcarrier 46′.

With reference to FIGS. 1M-1T, aspects and features of a rotor assembly20″ are illustrated in accordance with another example of the presentdisclosure. The rotor assembly 20″ is similar to the rotor assembly 20′discussed above with respect to FIGS. 1K and 1L. For example, the rotorassembly 20″ can include a disk carrier 46″ and rotor assembly disks asdescribed herein. The plurality of disks identified by reference number21 above have been omitted from these figures for clarity. FIG. 1M showsouter support disks 57 a′, 57 b′ and an inner support disk 57 c′ coupledto the disk carrier 46″. FIG. 1N shows an exploded view of the outersupport disks 57 a′, 57 b′ relative to the disk carrier 46″. The diskcarrier 46″ can have a disk coupling interface portion 61′ and one ormore of the rotor assembly disks can have a carrier coupling interfaceportion, as described above, to facilitate coupling the disks and thedisk carrier to one another. For example, the outer support disks 57 a′,57 b′ can have complementary coupling interface portions for the diskcarrier 46″ as described above, and the plurality of disks (not shown)can have complementary coupling interface portions in the same manner asillustrated for the support disks 57 a′, 57 b′. In addition, as with theembodiment described above with respect to FIGS. 1K and 1L, fluidpassageways 47″ of the disk carrier 46″ can be defined at least in partby spans 79′ in a disk portion 83″ extending along the axis of rotation1.

In this case, the disk carrier 46″ includes a mid-span support 79 acoupled to the spans 79′. In some embodiments, the mid-span support 79 acan be integrally formed with the spans 79′ (e.g., fixedly coupled toone another, such as by welding). The mid-span support 79 a can extendcircumferentially about the disk carrier 46″ to provide support for thespans 79′. The inner support disk 57 c′ is shown isolated from otherrotor assembly disks in an assembled configuration with the disk carrier46″ in FIG. 1O, and in an exploded or disassembled configuration in FIG.1P. The disk carrier 46″ is shown isolated in FIGS. 1Q and 1R, and theinner support disk 57 c′ is shown isolated in FIGS. 1S and 1T. In oneaspect, the inner support disk 57 c′ can be configured to couple withthe mid-span support 79 a. For example, the inner support disk 57 c′ canhave a span support coupling interface portion 63 b and the mid-spansupport 79 a can have a support disk coupling interface portion 61 b(FIG. 1P). In the illustrated embodiment, the coupling interfaceportions 61 b, 63 b comprise respective recesses 79 b, 79 c that combineto form a keyway 79 d (FIG. 1O) into which a key (not shown) may beinserted to provide torque transfer between the inner support disk 57 c′and the disk carrier 46″. It should be recognized that the couplinginterface portions 61 b, 63 b can have any suitable configuration thatcouples the inner support disk 57 c′ and the mid-span support 79′ to oneanother in a manner (e.g., one or more interfacing protrusions asdescribed above) to transfer torque between the components about theaxis of rotation 1. Although the coupling aspect of the mid-span support79 a has been shown and described as being operable to couple the innersupport disc 57 c′ with the disk carrier 46″, it should be recognizedthat outer support disks may be coupled to a disk carrier in a similarmanner.

In one aspect, with the mid-span support 79 a, a central chamber of thedisk carrier 46″ can remain unobstructed to fluid flow, such as byincluding a central aperture that forms a portion of the centralchamber, thus allowing fluid to pass entirely through the disk carrier46′. Alternatively, the mid-span support 79 a can be configured toextend through the disk carrier 46″ and partition a central chamber ofthe disk carrier, thus blocking or obstructing the central chamber localto the mid-span support 79 a. In this case, fluid is prevented frompassing entirely through the disk carrier 46″, as the central chamberhas been separated and subdivided by the mid-span support 79 a.

Notably, the rotor assembly discussed in connection with the diskcarrier can readily be incorporated into the housing, partition, inletsand other features discussed herein with respect to FIGS. 2-22C.Therefore, this description explicitly encompasses variations of thesystem where the rotor assembly of FIG. 1A-1P are used within thevariations discussed subsequently herein. Similarly, features andvariations regarding disk shapes, parameters, tapering, and the likewhich are discussed in other embodiments are also equally applicable tothe rotor assembly including a disk carrier.

With reference to FIG. 2 , a boundary layer turbomachine 100 isillustrated in accordance with an example of the present disclosure.FIGS. 3A-3B illustrate exploded views of the boundary layer turbomachine100 for further reference. The boundary layer turbomachine can include ahousing 110, which can include complementary housing portions 111 a, 111b. The housing can also have an inlet opening 112 and an outlet opening113 to facilitate movement of a fluid (i.e., a gas and/or a liquid)through the housing. The outlet opening 113 can be located at or near arotational axis 101 of a rotor assembly 120 while the inlet opening 112can be located on the housing 110 radially outward from the rotationalaxis 101. Although the rotor assembly 120 is shown and described in thecontext of one embodiment of a rotor assembly, it should be recognizedthat the boundary layer turbomachine 100 and other boundary layerturbomachines disclosed herein can include any suitable embodiment of arotor assembly, such as those disclosed herein.

In addition, although reference numbers 112, 113 have identified aninlet opening and an outlet opening of the housing 110, respectively, itshould be recognized that in some embodiments opening 113 can be aninlet opening and opening 112 can be an outlet opening based onoperation of the boundary layer turbomachine. In one aspect, theboundary layer turbomachine can be designed and operated as“directional” in that the flow of fluid always enters the housing viathe same inlet opening and exits the housing via the same outletopening. In another aspect, the boundary layer turbomachine can bedesigned and operated as “bidirectional” in that the flow of fluid canbe switched to enter the housing via either opening 112, 113 and exitthe housing via the other opening to obtain forward and reverse fluidflow. In addition, the housing can include an opening 114 (FIG. 3B) thatcan also serve as an inlet and/or an outlet similar to the opening 113.When both openings 113, 114 are utilized they will typically have thesame function. Thus, opening 112 can serve as an inlet opening, andopening 113 and/or opening 114 can serve as outlet openings. On theother hand, opening 113 and/or opening 114 can serve as inlet openings,and opening 112 can serve as an outlet opening. In some embodiments,multiple openings, which can serve as inlet and/or outlet openings, canbe located on the housing 110 radially outward from the rotational axissimilar to opening 112.

As illustrated in FIGS. 3A and 3B, the housing 110 can define aninterior space 115 to accommodate a rotor assembly 120. The rotorassembly can be configured to rotate about the axis of rotation 101. Therotor assembly can have a plurality of disks 121 spaced apart along theaxis of rotation. In one aspect, the disks can be substantially planarand oriented perpendicular to the axis of rotation, although anysuitable disk configuration can be utilized, such as a conical diskconfiguration. For example, non-planar disks can be nested to form arotor assembly using the principles described herein. Regardless, thedisks can be substantially parallel to one another throughout.Furthermore, any suitable number of disks can be utilized (e.g.,depending on power requirements). As described in more detailhereinafter, the plurality of disks 121 can define an interior opening(internal to the plurality of disks 121 and hidden from view) along theaxis of rotation. Thus, fluid can pass through gaps between the disksand the interior opening as the fluid moves through the housing from theinlet opening 112 to the outlet opening 113 and/or 114.

The rotor assembly 120 can also include an extension member 122 a, 122 bto couple the rotor assembly to the housing 110 and facilitate rotationof the rotor assembly about the axis of rotation 101. For example, theextension members 122 a, 122 b can be attached to the plurality of disks121 opposite one another and substantially inline to facilitate rotationof the rotor assembly about the axis 101. The extension members 122 a,122 b can be attached to the plurality of disks 121 using an adhesive,fasteners, or any other suitable substance or device. For example, theextension member can include a flange 123 a, 123 b to interface with theplurality of disks and facilitate coupling with the disks. The extensionmembers 122 a, 122 b can be mounted on bearings when coupled to thehousing 110 to provide low friction rotational interface. In onealternative, the bearings can be brush bearing seals. In one aspect, theextension members 122 a, 122 b can include vent ports 125 a, 125 bextending through the extension members in fluid communication with theinterior opening formed by the plurality of disks 121. Thus fluid canexit or enter the housing via the extension member vent ports 125 a, 125b, which extend through the housing openings 113, 114, respectively.

Although the various components of the boundary layer turbomachine 100can be constructed of any suitable material, in one aspect the rotorassembly 120 (i.e., the plurality of disks 121, the extension member 122a, and/or the extension member 122 b) and/or the housing 110 (i.e., thehousing portion 111 a and/or the housing portion 111 b) can be made inwhole or in part from a composite material, such as carbon fibercomposite (e.g., Toray T800S), basalt fiber composite, or any othersuitable lightweight structural material. In one example, the pluralityof disks can be formed of a woven fiber composite material (e.g.warp/weft). In one case, the woven fiber material can be a basalt fibermaterial such as, but not limited to, commercially available 15582/50material can be used. In another example, the plurality of disks 121 canbe formed of a ceramic composite material, which may be advantageous forhigh temperature applications. As a general guideline, the rotorassembly 120 can be designed to provide a low mass to surface arearatio. Typically, a lower mass to surface area ratio provides improvedperformance as long as sufficient strength is maintained in the rotorassembly. In some cases, the rotor assembly 120 can be provided as acomplete unit as a replacement of a damaged or worn rotor assembly.

In one aspect, the extension member 122 a, 122 b can facilitate couplingthe rotor assembly 120 to a generator or a motor. For example, theextension member 122 a, 122 b can include a flange 124 a, 124 b tointerface with a generator shaft or a motor shaft and facilitatecoupling the rotor assembly 120 to the generator or motor, such asutilizing fasteners, etc. A generator (e.g., an electric generator or apump) can be coupled to the rotor assembly 120 to generate power as thefluid moves through the housing 110. A motor can be coupled to the rotorassembly 120 to cause rotation of the rotor assembly, thereby causingmovement of the fluid through the housing 110 and utilizing the boundarylayer turbomachine 100 as a pump. The extension member 122 a, 122 b cantherefore serve as a mechanical transfer coupling for the rotor assembly120 to an external device, such as a generator or a motor. Any suitablegenerator or motor can be utilized with the boundary layer turbomachine100. In one aspect, each housing portion 111 a, 111 b can be coupled toa generator or a motor. For example, the housing portions 111 a, 111 bcan include mounting features 116 a, 116 b, respectively, to interfacewith a generator or a motor and facilitate coupling the housing 110 tothe generator or motor, such as utilizing fasteners, welds, etc. In oneaspect, the mounting feature 116 a, 116 b can extend at least as far asthe extension member 122 a, 122 b to facilitate directly attaching thehousing 110 to a generator or motor without interference from theextension member 122 a, 122 b. In addition, the boundary layerturbomachine 100 can be operated with the axis of rotation 101 in anysuitable orientation, such as vertical or horizontal.

When utilizing the boundary layer turbomachine 100 with a generator, theboundary layer turbomachine can be powered by steam from a number ofdifferent sources, such as capturing waste heat from a boiler, injectingwater directly into the exhaust stream of a liquid fuel generator byreplacing the muffler, or by generating its own heat content from acombustor. For example, combustion gases can be directly used as aworking fluid. Each of these configurations can utilize many of the samecomponents, such as a feedwater tank, pumps, sensors, computers, andother electronic components. Thus, water can enter the boundary layerturbomachine 100 as steam and can exit as a liquid, although any fluidwithin a wide range of pressures and temperatures may be used, which candepend on the material and resin properties when boundary layerturbomachine components are constructed of a carbon fiber composite.Alternatively, the turbomachine can have any number of fluids as aworking fluid medium such as, but not limited to, gases, vapors,liquids, suspensions, and combinations (e.g. multi-phase fluids).

In one aspect, the boundary layer turbomachine 100 can include apartition 130. As more clearly illustrated in FIGS. 4A and 4B, thepartition 130 can circumferentially divide the interior space 115 intoan outer chamber 116 and a rotor chamber 117 located radially inward ofthe outer chamber. The outer chamber 116 can be an annular volume havinggenerally having an inner radial dimension 102 of 80 to 95% of a radius103 of the interior space 115. As shown in FIG. 4B, the rotor assembly120 can be disposed in the rotor chamber 117. The outer edge of therotor assembly can be spaced a radial rotor gap distance apart from theinner edge of partition members 132. The radial rotor gap can generallybe 85 to 95% of a rotor chamber radius measured to the inner edge. Inone aspect, the radial gap distance can be equal to 3 to 8 times aboundary layer thickness of the fluid. Despite the rigidity of mostmaterials used for the rotor disks 121, the associated rate of spinduring operation can often result in radial elongation of from 1% to 5%.The rotor gap can vary depending on size, but is often from 1 mm to 2 cmat a resting condition. Accordingly, the rotor gap can be designed toaccommodate such disk stretching. Notably, operating speeds can varyconsiderably. However, in many cases the rotor assembly can operate atspeeds of 500 rpm up to 100,000 rpm, and in some cases, at speeds of2,000 rpm up to 8,000 rpm as a working range with loading, and in othercases from 1,000 rpm to 20,000 rpm. As a general guideline largerdiameter disks can often operate a relatively lower rpms than smallerdiameter disks.

The partition 130 can have partition openings 131 such that fluid ismovable through the partition between the outer chamber 116 and therotor chamber 117. In one aspect, the opening 112 can be associated withthe outer chamber 116 such that the outer chamber serves as an expansionchamber for the fluid when the opening 112 is an inlet opening.Typically, although not required, the inlet can also be oriented toproduce tangential flow within the expansion chamber. The partitionopenings 131 can be spaced (e.g., equally) circumferentially around thepartition 130 so as to allow fluid to move from the outer chamber 116into the rotor chamber 117 and, thus, into gaps between the disks of therotor assembly 120, at multiple locations around the outer edge of thedisks. This configuration offering multiple access ports from the outerchamber 116 to the rotor assembly 120 disks can increase the efficiencyof the turbomachine, particularly when the partition openings 131 areequally spaced from one another. In one aspect, the partition openings131 can be defined by two or more partition members 132 or formed in asingle partition member. As shown in FIG. 4B, the partition members 132can be arranged in a circular configuration with an internal diametersized to accommodate the rotor assembly 120 disks (i.e., larger than theouter diameter of the disks). The partition 130 (i.e., partition members132) can be an individual component which is secured in place, orintegrally formed with the housing, such as housing portion 111 a. Inthe embodiment illustrated in FIGS. 4A and 4B, the partition members 132illustrated are merely one-half of the partition 130, with acomplementary set of partition members secured to the opposite housingportion 111 b. Alternatively, the partition can be formed as a singleset of partition members in order to avoid misalignment of complementarypartition members.

In one aspect, the partition openings 131 can comprise a venturiconfiguration. The term “venturi” is used herein to generally define aconfiguration wherein the partition opening 131 formed by two spacedapart complementing surfaces 133, 134 of adjacent partition members 132converges and/or diverges such that fluid passing through the partitionopening reaches enhanced speed while concurrently developing asignificantly reduced pressure producing an effect similar to theVenturi effect. Any suitable venturi configuration can be utilized. Inone aspect, the partition openings 131 can have an injection angle 104of 25 to 55 degrees relative to an at least partially planar surface133. In some cases, the injection angle 104 can range from 30 to 50degrees, and in one specific example 41.5 degrees. Alternatively, theinjection angle 104 can range from 35 to 65 degrees, in some cases from40 to 60 degrees, and in one specific example 51.4 degrees. In anotheraspect, the partition openings 131 can have a radial dimension 105 of 5mm to 5 cm. In yet another aspect, the partition openings 131 can havean outer circumferential dimension 106 of 5 mm to 5 cm and an innercircumferential dimension 107 of 1 cm to 10 cm. The angle 104, radialdimension 105, outer circumferential dimension 106, and innercircumferential dimension 107 can vary depending on the fluid type,size, and application of the turbomachine.

In one aspect, the partition openings 131 can be reconfigured during useto facilitate bidirectional flow of fluid through the housing, or tofine tune performance for particular settings and environments. Forexample, the configuration (i.e., the angle 104, radial dimension 105,outer circumferential dimension 106, and/or inner circumferentialdimension 107) of the partition openings 131 can be controlled bymanipulating one or more partition members 132 via a motor, which can beactuated by one or more switches to achieve suitable flowcharacteristics through the partition openings in two directions.Alternatively, the partition member orientations can be adjusted using amanual or mechanical linkage to move the partition members relative toone another. Typically, partition members can be adjusted uniformly sothat each partition member is moved an equal distance to maintainuniform angle and distances throughout the partition, although in someaspects the partition members can be independently adjustable. Optimalangles, spacing and configuration can be at least partially dependent onfluid medium (including temperature, phase, etc), fluid velocity,boundary layer disk gap distance, disk roughness, and the like.

In one aspect, the outer chamber 116 (i.e., an expansion chamber in someembodiments) can have a constant or uniform cross-sectional area, suchas by maintaining dimensional characteristics and geometry for a full360 degrees about the axis of rotation 101. Notably, the expansionchamber in this case does not include inlet opening 112 space leading upto the expansion chamber. In the illustrated embodiment, the outerchamber 116 has a cylindrical configuration with the cross-sectionalarea being uniform about the outer chamber 116 through a constantcylindrical wall thickness.

In a steady operational state where fluid enters the housing via theopening 112, the fluid circulates around the outer chamber 116 andmaintains a relatively constant pressure regime within the outerchamber. The fluid passes through the partition openings 131 into therotor chamber 117 and enters the spaces or gaps between the individualdisks 121 within the rotor assembly 120. By adhesive and viscous actionon the surfaces of the disks the fluid causes the disks to rotate. Asthe rotational speed of the disks increases, the fluid between the disksis acted upon by both centrifugal force and the pressure differencemaintained between the outer chamber 116 and the partition openings 131,which causes the fluid to be retained within the disks. This increasedresidence of the fluid between the disks enables the fluid to continueto transfer energy and do work by imparting further rotation in the formof torque, which increases efficiency and allows the turbomachine toconvert more thermal energy to mechanical work.

In one aspect, a debris trap 140 can be included to gather and expelheavier particles thrown to the outer edges of the rotor assembly 120disks by centrifugal force. For example, a portion of the partition 130can form the debris trap 140 as shown in FIGS. 4A and 4B in the shape ofa channel or groove along an inner radial surface of one or more of thepartition members 132. The debris trap 140 can convey the particles fromthe interior space 115 via an opening 141, which can lead to a debrisreceptacle 142 external to the housing 110 via a conduit 143, as shownin FIGS. 2 and 3A. The illustrated debris trap includes openings 141 ateach end, although a single opening may be suitable. The debrisreceptacle 142 can be easily serviced and cleaned utilizing steampressure and gravity. The debris trap 140 can therefore captureparticles from the fluid and prevent the particles from leaving theturbomachine as emissions. In certain applications this can dramaticallyreduce the environmentally negative emissions associated with typicalexisting technologies.

In one aspect, the opening 112 can be configured as an adaptive inletport to provide the optimal efficiency intake pressure and/or flowpattern for the fluid. For example, as shown in FIG. 4B, a modular,replaceable inlet fitting 118 can optionally be used to providedifferent orifice or inlet opening sizes as desired to affect the intakepressure and/or flow pattern of the fluid. Alternatively, the inletmanifold 144 can include replaceable inserts across a width of themanifold.

FIG. 5 illustrates a disk 250 that can be utilized in a rotor assemblyin accordance with an example of the present disclosure. As shown in thefigure, the disk 250 can include a plurality of fluid guides 251. Thefluid guides can have any suitable cross-section such as, but notlimited to, airfoil, elliptical, circular, diamond, and the like.However, an airfoil cross-section as illustrated can be particularlyeffective. The fluid guides 251 can be arranged in a ring configuration252 a, 252 b, and/or 252 c across the disk 250. In one aspect, the ringconfiguration can comprise multiple rings 252 a-c concentric about theaxis of rotation 201. Although three such rings are illustrated, fromabout three to about eight rings can often be suitable depending on thesize and design operating parameters. In another aspect, a radialrelationship of the rings 252 a-c can correspond to the Fibonacci ratio(1.61618) or the Golden ratio (1.61803) to maximize the efficiency ofthe fluid as the fluid follows a spiral flow path along the disk 250.However, other radial relationships can be used such as equidistant, orratios of 1.2 to 2, for example. As the fluid first encounters the fluidguides 251 a pressure wave is formed, which upon passing forms a lowpressure vortex area that adds further impulse in the form of mechanicaltransfer of energy to the (rotating) disk in addition to the force(s)already present (e.g., adhesion and viscous forces acting on therotating rotor assembly). When using airfoil shaped fluid guides, aninclination angle can be adjusted based on desired operating parameters.As a general guideline, the inclination angle 253 (i.e. an angle betweena rotor radius 254 and central longitudinal airfoil axis 255) can befrom about 20° to about 75°, and in some cases 30° to 55°. The number,geometric design, and location of the fluid guides 251 on the disk 250can be optimized based on the size of the disk, the inlet pressure, andthe design speed of rotation of the rotor assembly. In one aspect, aventuri configuration of a partition opening (see FIGS. 4A and 4B) cancontrol the fluid flow between the concentric rings 252 a-c. As therotational velocity of the rotor assembly increases, fluid flowincreases towards the center of the disks. At lower rotational velocity,fluid flow tends towards the outer edges of the disks.

FIG. 6 illustrates adjacent disks 350 a, 350 b of a rotor assembly inaccordance with an example of the present disclosure oriented to show agap between the disks. The disks 350 a, 350 b of a rotor assembly aretypically relatively thin (e.g., a thickness 356 of approximately 1.45mm) and typically have a gap 357 or space between the disks of adistance 358 equal to or less than the disk thickness 356. Moregenerally, the disk thickness 356 can be from about 2 to 5 times aboundary layer thickness of the fluid, often from 3 to 5, and most oftenabout 3. Similarly, the disks 350 a, 350 b can be spaced apart by adistance 358 equal to 3 times a boundary layer thickness of the fluid,although from about 0.25 to 8 can be used, in some cases 1 to 5, oftenfrom 2 to 5, and most often about 3 times the boundary layer thickness.Generally, disk thickness can range from about 0.5 mm to about 5 mm, andin some cases from about 0.8 mm to about 2 mm. In one aspect, the outeredges of the disks 350 a, 350 b can be tapered by an angle 359 to athinner edge of small radius to provide a tapered zone that can lessenturbulence and facilitate a smooth transition of fluid flow into or outof the rotor assembly.

FIG. 7 illustrates a cross-section of a portion of a rotor assembly 420in accordance with an example of the present disclosure. The rotorassembly 420 includes a plurality of disks 421 (identified individuallyas disks 450 a-n) that defines a central hollow interior opening 426along an axis of rotation, which extends through the interior opening.The disks 450 a-n include a plurality of spacers 451 a-n disposedbetween adjacent disks to space the disks apart along the axis ofrotation to provide gaps 454 a-m between the disks. Thus, fluid can passthrough the gaps 454 a-m between the disks 450 a-n and the interioropening 426 as the fluid moves through the rotor assembly 420.

In one aspect, the disks 450 a-n can be permanently coupled to oneanother by the plurality of spacers 451 a-n, such as using an adhesive.In one example, the adhesive is a common resin binder used to form theentire assembly. In one aspect, the interior opening 426 can be acentral hollow void, free of any solid structure (e.g., a shaft or othersimilar structure) that would couple or secure the disks 450 a-n to oneanother and/or transfer torque. In another aspect, the interior openingcan include a central hollow void as well as a disk carrier (e.g. FIG.1A-1L) as disclosed herein, which can be coupled to the disks 450 a-nfor support and/or to transfer torque. Thus, solid structures areexcluded from the central hollow void of the interior opening 426 alongthe entire length of the plurality of disks 421 and, in someembodiments, along the entire length of a rotor assembly. Such aconfiguration also results in fluid ingress and egress from both ends ofthe interior opening.

As shown in FIG. 7 , the spacers 451 a-n can be integrally formed withthe disks 450 a-n. Thus, by utilizing such built-in spacers 451 a-n tocouple the disks 450 a-n to one another, no other parts are needed tocomplete the disk assembly. In one aspect, the spacers 451 a-n can havean airfoil configuration and can therefore also serve as fluid guides asdiscussed above with reference to FIG. 5 . As illustrated in FIG. 7 ,the disks 450 a-n can be flat on one side and can have spacersprojecting from an opposite side, which can be set out or arranged in aring configuration as discussed above. Thus, the spacers 451 a-n canensure precise and proper spacing of the disks 450 a-n from one anotherand contribute rigidity to the rotor assembly 420 structure underoperating loads by providing multiple, geometrically and radiallydistributed coupling locations to interlock adjacent disks. In addition,utilizing adhesive to bond the spacers 451 a-n to adjacent disksprovides a fixed attachment condition in all degrees of freedom thatincreases stiffness over a simpler attachment condition without fixityin all degrees of freedom, such as a bolted coupling. Typically, therotor assembly 420 will include from 60 to 200 disks having gapdistances of 0.5 mm to 5 mm, although any suitable number and spacing ofdisks can be utilized. Although the number of disks within a rotorassembly can vary, as a general guideline, from 50 to 500 disks, and insome cases from 75 to 200 disks can be included. In some embodiments,identical disks can be used to construct the entire rotor assembly 420(including outer end disks), thus simplifying construction. In otherembodiments, disks of different configurations can be incorporated intothe rotor assembly, such as disks having different spacer/fluid guideconfigurations. In one example, a “smooth” disk can be used to “cap” anend of the rotor assembly disks, thus providing smooth exposed diskfaces on opposite ends of the rotor assembly. Alternatively, holes canbe placed on outer plates of the disk pack which allows condensed waterto escape freely into the shaft which could otherwise act as a waterbreak.

The disks and other portions of the device can generally be formed ofany material having suitable mechanical strength and rigidity. Asnon-limiting examples, the disks can be formed of lightweight compositematerials, metal alloys, ceramics, and the like. Lightweight compositematerials can include, but are not limited to, carbon fiber, basaltfiber, fiberglass, and the like. Such fiber-based materials can also bewoven so as to increase rigidity against excessive stretching duringoperation. Non-limiting examples of suitable metals can includetitanium, tungsten, magnesium alloys, aluminum, steel, tantalum,vanadium, alloys thereof, composites thereof, and the like. Ceramics andsuitable ultrahard materials can include, but are not limited to,carbides, nitrides, polycrystalline diamond (PCD and CVD), and the like.The disks can be monolithic in composition or coated (e.g. metal corewith a ceramic or PCD outer coating). In one aspect, the disks of therotor assembly can be constructed of lightweight composite material(e.g., carbon fiber and/or basalt fiber), which can provide a highsurface area with less mass compared to typical designs that relyheavily on a “flywheel” effect to preserve momentum, unlike aturbomachine of the present disclosure.

FIG. 8 illustrates a cross-section of a portion of a rotor assembly 520in accordance with another example of the present disclosure. As withFIG. 7 , the rotor assembly 520 includes a plurality of disks 521 thatdefine a central hollow interior opening 526 along an axis of rotation,which extends through the interior opening. Accordingly, fluid movingthrough gaps between adjacent disks can freely enter or exit theinterior opening 526 directly from the gaps. In this case, however, theinterior opening 526 is also defined at least in part by a helicalbaffle 527 to facilitate directional flow or movement of fluid throughthe rotor assembly 520 for venting fluid from the rotor assembly. Insome embodiments, the helical baffle 527 can be formed by a feature orprotrusion on each disk such that when the disks are assembled thebaffle is formed with gaps in the baffle between adjacent disks. Inother embodiments, the helical baffle 527 can be a separate componentadded to the disk assembly such that the baffle extends across the gapsbetween adjacent disks.

An extension member 522 is also shown attached to the plurality of disks521. The extension member 522 can be attached to the plurality of disks521 using an adhesive, fasteners, or any other suitable substance ordevice. For example, the extension member 522 can include a flange 523to interface with the plurality of disks 521 and facilitate couplingwith the disks. The extension member 522 also includes a vent port 525oriented along the axis of rotation. The vent port 525 can extendthrough the extension member 525 in fluid communication with theinterior opening 526 formed by the plurality of disks, thus effectivelyforming an extension of the interior opening. Although a diameter of thevent port 525 is illustrated as being different than a diameter of theinterior opening 526, it should be recognized that the vent port and theinterior opening can have substantially the same diameter to facilitateunrestricted fluid flow between the interior opening and the vent port.

The helical baffle optionally extends across an extension member 522. Inone aspect, the vent port 525 can be defined at least in part by ahelical baffle 528 to facilitate movement of the fluid through the ventport 525. As with the helical baffle 527 of the internal opening 526,the helical baffle 528 can be a protruding internal surface featureintegrally formed with the substrate or included as a separatecomponent. The helical baffles 527, 528 can be continuous through theinterior opening 526 and the vent port 525 such that the interfacingends of the baffles align with one another to maintain the flow ormovement of fluid through the rotor assembly 520 for venting fluid fromthe rotor assembly. Although interior opening 526 and the vent port 525are shown with the helical baffles 527, 528, it should be recognizedthat the interior opening and the vent port can have smooth orfeatureless boundaries, which can simplify construction of the rotorassembly 520.

FIGS. 9A and 9B illustrate a computer model showing the fluid volume inan interior space of a boundary layer turbomachine in accordance with anexample of the present disclosure. These figures show fluid in the inletopening, the outer chamber, the partition openings, the rotor chamber,the interior opening, and the vent port.

With reference to FIGS. 10A and 10B, a boundary layer turbomachine 600is illustrated in accordance with another example of the presentdisclosure. The boundary layer turbomachine can include a housing 610.The housing can have openings 612, 613, which can serve as inlet oroutlet openings, based on operation of the boundary layer turbomachine,to facilitate movement of a fluid (i.e., a gas and/or a liquid) throughthe housing, as illustrated by inlet/outlet flow directions 608, 609.Notably, the turbomachine can utilize multi-phase systems as the workingmedium including liquids, vapors, gases, and combinations of these,including solid suspended fine particles. The opening 613 can be locatedon or about a rotational axis of a rotor assembly 620 while the opening612 can be located on the housing 610 radially outward from therotational axis. The partition members are obscured but orientedcircumferentially between the rotor assembly 620 and inner surface ofthe housing 610 as described with reference to FIGS. 3A and 3B. FIGS.11A and 11B illustrate views of the rotor assembly 620 isolated from thehousing 610 for further reference. In one aspect, the boundary layerturbomachine can be designed and operated as “directional” in that theflow of fluid always enters the housing via the same inlet opening andexits the housing via the same outlet opening. In another aspect, theboundary layer turbomachine can be designed and operated as“bidirectional” in that the flow of fluid can be switched to enter thehousing via either opening 612 or 613 and exit the housing via the otheropening to obtain forward and reverse fluid flow. In some embodiments,multiple openings 612, which can serve as inlet and/or outlet openings,can be located on the housing 610 radially outward from the rotationalaxis. Thus, any suitable number of openings 612 can be included and canbe formed by an opening manifold 644 or conduit.

The housing 610 can define an interior space 615 to accommodate therotor assembly 620. The rotor assembly can be configured to rotate aboutan axis of rotation. The rotor assembly can have a plurality of disks621 spaced apart along the axis of rotation, as described above, thatdefine an interior opening 626 along the axis of rotation. Thus, fluidcan pass through gaps between the disks and the interior opening as thefluid moves through the housing between the opening 612 and the opening613.

The rotor assembly 620 can also include an extension member 622 coupledto the plurality of disks 621. In one aspect, the extension member 622can include a vent port 625 extending through the extension member influid communication with the interior opening 626 formed by theplurality of disks 621. Thus, fluid can exit or enter the housing viathe extension member vent port 625, which may extend through the housingopening 613.

In addition, the rotor assembly 620 can include a mounting plate 660coupled to the plurality of disks 621. The extension member 622 and themounting plate 660 can be attached to the plurality of disks 621 usingan adhesive, fasteners, or any other suitable substance or device. Themounting plate 660 can form a barrier to fluid passing through theinterior opening 626, such that the fluid must flow either through thevent port 625 or the gaps between the disks as the fluid passes throughthe interior opening 626.

The rotor assembly 620 can further include a base 664 coupled to themounting plate 660 via a connecting member 662. The base 664 can bedisposed at least partially within the interior space 615 of the housing610. In one aspect, the base 664 can be used to couple the rotorassembly 620 to the housing 610 and facilitate rotation of the rotorassembly about the axis of rotation 601. The base 664 can be mounted onbearings when coupled to the housing 610 to provide a low frictionrotational interface. In one aspect, boundary layer turbomachine 600 canbe constructed in a modular manner, where the housing 610 and the rotorassembly 620 are interchangeable with like components to achieve adesired result. Thus, the base 664 can be configured to “float” alongthe axis of rotation to accommodate any suitable number of disks thatmay be included in a given rotor assembly. In some embodiments, the base664 can be adjusted in size as the number of disks changes to maintain aconsistent stack height of the rotor assembly, although this need not bethe case. The housing 610 can include a shoulder 619 configured to belocated proximate the plurality of disks at location 628. The shoulder619 can at least partially define a region radially outward from theplurality of disks 621 within the interior space 615 to facilitate thepassage fluid through the housing 610 to or from the gaps in theplurality of disks 621.

In one aspect, the base 664 and/or the extension member 622 canfacilitate coupling the rotor assembly 620 to a generator, a motor, adrive shaft, etc. A generator (e.g., an electric generator or a pump)can be coupled to the rotor assembly 620, such as via the base 664, togenerate power as the fluid moves through the housing 610. A motor canbe similarly coupled to the rotor assembly 620 to cause rotation of therotor assembly, thereby causing movement of the fluid through thehousing 610 and utilizing the boundary layer turbomachine 600 as a pump.The base 664 and/or the extension member 622 can therefore serve as amechanical transfer coupling for the rotor assembly 620 to an externaldevice, such as a generator or a motor. Any suitable generator or motorcan be utilized with the boundary layer turbomachine 600. In addition,the boundary layer turbomachine 600 can be operated with the axis ofrotation in any suitable orientation, such as vertical or horizontal.

Although the various components of the boundary layer turbomachine 600can be constructed of any suitable material, in one aspect the rotorassembly 620 (i.e., the plurality of disks 621, the base 664, theconnecting member 662, and/or the extension member 622) and/or thehousing 610 can be made in whole or in part from carbon fiber composite(e.g., Toray T800S) or any other suitable lightweight structuralmaterial. As a general guideline, the rotor assembly 620 is designed toprovide a low mass to volume ratio. In some cases, the rotor assembly620 can be provided as a complete unit as a replacement of a damaged orworn rotor assembly.

FIG. 12 illustrates a rotor assembly 720 in accordance with anotherexample of the present disclosure. As with the rotor assembly 620described above, the rotor assembly 720 includes mounting plate 760coupled to a plurality of disks 721, a base 764, and a connecting member762. In this case, however, the base 764 includes an opening 766configured to accommodate a motor 770, which is coupled to the mountingplate 760 via the connecting member 762. The base 764 can include anopening 768 through which the connecting member 762 can extend. Thus, inthis embodiment, the base 764 can be fixed relative to a housing and themotor 770, while the connecting member 762 serves as a drive shaft fromthe motor to cause rotation of the plurality of disks 721.

With reference to FIG. 13 , a boundary layer turbomachine 800 isillustrated in accordance with another example of the presentdisclosure. FIGS. 14A-14B illustrate partially exploded views of theboundary layer turbomachine 800 and FIGS. 15A and 15B illustratecross-sectional views of the boundary layer turbomachine 800 for furtherreference. As with other examples disclosed herein, the boundary layerturbomachine 800 can include a housing 810, which can include any numberor configuration of housing portions in order to surround or enclosedisks 821 of a rotor assembly 820 (FIG. 15A). A cross-section of thehousing 810 without the rotor assembly 820 is shown in FIG. 15B and therotor assembly 820 is shown isolated in FIG. 18 for further reference.

The housing 810 can have openings 812-814 to facilitate movement of afluid (i.e., a gas and/or a liquid) through the housing. The openings813, 814 can be located at or near a rotational axis 801 of the rotorassembly 820 while the opening 812 can be located on the housing 810radially outward from the rotational axis 801. The openings 812-814 canserve as inlet or outlet openings depending on the direction of flowthrough the housing 810. For example, opening 812 can serve as an inletopening, and opening 813 and/or opening 814 can serve as outletopenings. On the other hand, opening 813 and/or opening 814 can serve asinlet openings, and opening 812 can serve as an outlet opening. Theboundary layer turbomachine 800 can be designed and operated as“directional” in that the flow of fluid always enters the housing 810via the same inlet opening and exits the housing via the same outletopening, or the boundary layer turbomachine can be designed and operatedas “bidirectional” in that the flow of fluid can be switched to enterthe housing via opening 812 or openings 813, 814 and exit the housingvia the other opening(s) to obtain forward and reverse fluid flow. Insome embodiments, multiple openings, which can serve as inlet and/oroutlet openings, can be located on the housing 810 radially outward fromthe rotational axis similar to opening 812.

As with other examples disclosed herein, the rotor assembly 820 can havea plurality of disks 821 spaced apart along the axis of rotation 801,which can define an interior opening 826 along the axis of rotation(FIG. 15A). Thus, fluid can pass through gaps between the disks and theinterior opening as the fluid moves through the housing 810, such asfrom the opening 812 to the opening 813 and/or 814.

As illustrated in FIGS. 15A and 15B, the housing 810 can define aninterior space 815 to accommodate the rotor assembly 820. In addition, apartition 830 can circumferentially divide the interior space 815 intoan outer chamber 816 and a rotor chamber 817 located radially inward ofthe outer chamber. When the opening 812 is an inlet opening, the housing810 can have a distribution region 880 between the inlet opening and theinterior space 815 to transition fluid flow from the inlet opening tothe interior space. In one aspect, the opening 812 can be associatedwith an inlet manifold 844, which can be configured to form an expansioninlet region 881. The expansion inlet region 881 and the distributionregion 880 can form a redirection chamber for the fluid, and the outerchamber 816 forms a distinct and separate expansion chamber for thefluid circumferentially about the partition 830. In one aspect, thedistribution region 880 and the outer chamber 816 can havecross-sectional areas perpendicular to fluid flow directions (e.g., asrepresented in FIG. 17 at 890 and 891, respectively) that are equal toone another, however, it should be recognized that some differences inthese areas can be acceptable. For example, the cross-sectional area 890of the distribution region 880 can vary from the cross-sectional area891 of the outer chamber 816 by as much as 100%. However, thecross-sectional area 890 of the distribution region 880 can most oftenvary from the cross-sectional area 891 of the outer chamber 816 by lessthan 10%, and in some cases is substantially equal (e.g. within about1%). Providing substantially equal cross-sectional areas 890, 891 canmaintain a constant velocity of the fluid and avoid eddy currents withinthe outer chamber 816. The manifold 844 can be configured as a modular,replaceable fitting that can be used to provide different inlet openingsizes and expansion region characteristics, as desired, to affect theintake pressure and/or flow pattern of the fluid. For example, themanifold 844 can have expansion surfaces 845 a, 845 b (FIG. 14B)configured to define the expansion region 881. The expansion surfaces845 a, 845 b can be sized and/or angled to provide desired expansionregion characteristics. In this configuration, the expansion surfaces845 a and 845 b can be tapered from an inlet diameter (i.e. associatedwith a circular inlet) to a narrower expansion height. In this manner,the inlet manifold 844 can progressively vary cross-sectional area froma circular inlet to a rectangular distribution region 880 cross section.Such progressive transition can help to reduce or eliminate eddies ordisturbances in fluid flow which can also reduce desirable laminar flow.Generally, laminar flow throughout the device can increase operatingefficiencies. Accordingly, transitions into the expansion region,interior space, outer region, disk gaps, outlets, and the like can beconfigured to reduce or substantially eliminate non-laminar flow.Although not required, the distribution region 880 can be oriented toproduce tangential flow within the outer chamber 816. A fluid drain 882can be associated with the housing 810 and in fluid communication withthe interior space 815 to drain liquid from the interior space.

The partition 830 can have partition openings 831 such that fluid ismovable through the partition between the outer chamber 816 and therotor chamber 817. The partition openings 831 can be spaced (e.g.,equally) circumferentially around the partition 830 so as to allow fluidto move from the outer chamber 816 into the rotor chamber 817 and, thus,into gaps between the disks of the rotor assembly 820, at multiplelocations around the outer edge of the disks. In one aspect, thepartition openings 831 can be defined by two or more partition members832 or formed in a single partition member. The partition members 832can be arranged in a circular configuration with an internal diametersized to accommodate the rotor assembly 820 disks (i.e., larger than theouter diameter of the disks). The partition members 832 can be spaced(e.g., equally) circumferentially around the rotor chamber 817. Thepartition 830 (i.e., partition members 832) can be an individualcomponent which is secured in place, or integrally formed with thehousing 810.

The partition openings 831 can comprise a venturi configuration formedby two spaced apart complementing surfaces 833, 834 of adjacentpartition members 832 that converges and/or diverges such that fluidpassing through the partition opening reaches enhanced speed whileconcurrently developing a significantly reduced pressure producing aneffect similar to the Venturi effect. Any suitable venturi configurationcan be utilized. In one aspect, each partition member 832 can have aninlet surface radius 835 forming a portion of a partition opening inlet836. The inlet surface radius 835 (e.g. radius of curvature) can beequal to a radial thickness 883 (i.e., a maximum radial thickness) ofthe partition member plus ½ the radial thickness. As a generalguideline, the inlet surface radius can be within 5%, and most oftenwithin about 1% of 1.5 times the radial thickness 883. In anotheraspect, each partition member 832 can have an outlet surface radius 837forming a portion of a partition opening outlet 838. The outlet surfaceradius 837 can be equal to one-third of the inlet surface radius 835,and generally at least within 20%, often within 5% of one-third theinlet surface radius 835. As illustrated, the surfaces 833 of thepartition members 832 can be planar in whole or in part, although anysuitable configuration can be utilized.

Any suitable number of partition members 832 can be utilized. In oneaspect, the number of the partition members 832 can be at least 8 andequal to the nearest or next larger even whole number of inches (e.g.units of 2.54 cm) within an outer diameter 892 of the plurality of disks821 divided by 2. In one aspect, at least 8 partition members 832 can beincluded regardless of the outer diameter of the disks 821. For example,10 partition members can be used with 19-inch diameter disks, and 8partition members can be used with 14-inch diameter disks. As shown inthe detail view of FIG. 17 , the position of the partition members 832can be established relative to the housing 810. In one aspect, one ofthe partition members 832 can be located such that a midpoint 885 of thepartition member is offset 886 by 51% (not shown to scale for clarity)of a length 889 of the partition member from a terminal point 887 of thehousing 810 defining a fluid inlet pathway or conduit 888, such as at atermination of the distribution region 880. However, the forward offset886 can in some cases be within about 1% of 51% of the length 889,although not less than 50% to avoid creation of eddies. The midpoint 885can represent a geometric center of a line 889 defining a length of thepartition member 832.

In one aspect, the outer chamber 816 (i.e., an expansion chamber in someembodiments) can have a constant or uniform cross-sectional area 891,such as by maintaining dimensional characteristics and geometry for afull 360 degrees about the axis of rotation 801, and in most cases atleast 330 degrees about the axis of rotation 801. It is noted that theouter chamber 816 does not include the partition openings 831 formedbetween adjacent partition members 832, or the distribution region 880.Thus, in the illustrated embodiment, the outer chamber 816 has acylindrical configuration with the cross-sectional area 891 beinguniform about the outer chamber 816 through a constant cylindrical wallthickness.

In order to scale the turbomachine 800, the diameter of the disks may beincreased and/or the number of disks may be increased. When increasingthe number of disks, the length of the turbomachine will increase alongthe axis of rotation. In one aspect, the disks can be configured in diskpacks or disk pack segments having a plurality of disks “bookended” byouter support disks. Such disk pack segments can include one or moreinner support disks as described above. Multiple disk pack segments canbe combined together on a common disk carrier (which may be acombination of multiple disk carriers) to suit a given design objective.In such cases, a turbomachine can include multiple inlets and/or outletsto facilitate movement of fluid through the turbomachine. In thismanner, multiple disk pack segments can form multiple correspondingfluid flow regions. In some embodiments, inlet/outlet regions within theturbomachine (e.g., within a common housing) can be physically separatedwith baffles or shrouds to substantially isolate fluid flow torespective inlet/outlet regions. In other embodiments, inlet/outletregions of a multiple fluid flow region configuration can have a commonexpansion chamber and/or common fluid outlet region.

FIG. 17 further illustrates an outer diameter edge 829 of the rotorassembly 820 spaced a radial rotor gap distance 884 apart from an inneredge or surface 839 of partition members 832. In one aspect, the radialdistance 884 can be equal to 6 times a boundary layer thickness of thefluid, in some cases from 3 to 10 times, and in some 3 to 8 times.Although distances can vary based on specific design parameters, theradial distance can generally be slightly higher when the turbomachineis configured as a pump. For example, in a pump configuration, theradial distance 884 may be about 2-10% higher than a similarlyconfigured turbine configuration. In either case, a range of 3 to 10times the boundary layer thickness can be suitable.

As shown in FIGS. 15A and 18 , the rotor assembly 820 can also includean extension member 822 a, 822 b to couple the rotor assembly to thehousing 810 and facilitate rotation of the rotor assembly about the axisof rotation 801. For example, the extension members 822 a, 822 b can beattached to the plurality of disks 821 opposite one another andsubstantially inline to facilitate rotation of the rotor assembly aboutthe axis 801. In one aspect, the extension members 822 a, 822 b can beattached to the plurality of disks 821, such as via outer support disks857 a, 857 b, using an adhesive, fasteners, or any other suitablesubstance or device. In another aspect, the extension members 822 a, 822b can be integrally formed with outer support disks 857 a, 857 b,respectively. In addition to providing an interface or structure forcoupling with the extension members 822 a, 822 b, the outer supportdisks 857 a, 857 b can be used to “cap” an end of the rotor assemblydisks, thus providing smooth exposed disk faces on opposite ends of therotor assembly. In one aspect, the disks of the rotor assembly 820 canbe constructed of lightweight composite material (e.g., carbon fiberand/or basalt fiber). In a particular aspect, the outer support disks857 a, 857 b can be constructed of a metal material (e.g., steel,aluminum, nickel, bronze, etc.), which may be of the same or a similartype of material used to construct the extension members 822 a, 822 b.

As shown in FIG. 15A, the extension members 822 a, 822 b can be mountedon bearings 865 a, 865 b when coupled to the housing 810 to provide lowfriction rotational interface, although other mounts can be used. Seals866 a, 866 b can be included to prevent or minimize leakage of fluidfrom the housing 810 around the extension members 822 a, 822 b. In oneaspect, the extension members 822 a, 822 b can include vent ports 825 a,825 b extending through the extension members in fluid communicationwith the interior opening 826 formed by the plurality of disks 821. Thusfluid can exit or enter the housing 810 via the extension member ventports 825 a, 825 b, which extend through the housing openings 813, 814,respectively.

Extension plates 823 a, 823 b can be attached to ends of extensionmembers 822 a, 822 b, respectively. The extension plates can be used tocouple to a suitable mechanical rotational energy capture device (e.g.driveshaft, belt, or the like). Fluids can be withdrawn through ventports 825 a, 825 b by coupling the extension plates with a rotationalcoupling to a fixed outlet conduit. Alternatively, the extension members822 a, 822 b can be elongated to extend well beyond the outer housing810. Fluid outlets can be distributed along the elongated portion toallow release of the fluids such that a fixed driveshaft or other membercan be attached at a distal end of the elongated portion while alsoallowing removal of the fluid from the system. Regardless, any number ofconfigurations can be used to couple a corresponding mechanical energycapture device while also allowing exit of fluid from the interioropening 826.

FIG. 19 illustrates a disk 850 that can be utilized in a rotor assemblyin accordance with an example of the present disclosure, such as therotor assembly 820 discussed above. As shown in the figure, the disk 850can include a plurality of spacers 851. The spacers 851 can have anysuitable cross-section such as, but not limited to, airfoil, elliptical,circular, diamond, and the like. The spacers 851 can be arranged in aring configuration across the disk 850 as illustrated. In one aspect,the spacers 851 can be confined to a region within one-half of a radius854 of the disk 850. In another aspect, the spacers 851 can be confinedto a region within one-third of the radius 854 of the disk 850.Centrally locating the spacers 851 (e.g. but not within the interioropen space) about the disk 850 can allow radially outward portions ofthe disk freedom to flex or deflect. Under operating conditions (e.g.,high rotational speed with fluid between adjacent disks), suchflexibility of the disks can be beneficial in that the disks can“self-adjust” in response to pressure differentials by equalizingdistance between adjacent disks, which can provide performance benefitsfor the turbomachine 800.

In one aspect, the spacers 851 can be configured as fluid guides. Inthis case, the spacers 851 can be oriented at an inclination angle 853,which can be selected based on desired operating parameters. As ageneral guideline, the inclination angle 853 (i.e. an angle between arotor radius 854 and a central longitudinal spacer axis 855) can be fromabout 20° to about 75°, and in some cases 30° to 55°. The number,geometric design, and location of the spacers 851 on the disk 850 can beoptimized based on the size of the disk, the inlet pressure, and thedesign speed of rotation of the rotor assembly. In one aspect, thenumber of spacers 851 can be equal to the number of partition members(e.g., partition members 832).

In one aspect, multiple disks 850 can be coupled to one anotherutilizing the spacers 851 to form the disks of a rotor assembly. Forexample, the spacers 851 can include holes or openings 866 a, 866 b andthe disk 850 can include holes or openings 867 a, 867 b (see, e.g., FIG.16 ), which are configured to receive a fastener (e.g., threadedfastener 869 of FIG. 15A) that can couple multiple disks to one another.In this example, two fasteners can be used to extend through and securean individual spacer 851 between adjacent disks 850, which can serve toprovide stability for the spacer during operation of the turbomachine.Thus, the fasteners can optionally be a plurality of bolts which passthrough the disks. Such fasteners can be distributed about the disks asdescribed in more detail herein. It should be recognized that,alternatively, spacers can be integrally formed with the disks. In oneaspect, aside from the exposed central opening in the disk 850 thatcombines to form an interior opening within a rotor assembly, the diskcan be solid with no windows or other fluid passageways when assembledin a rotor assembly. In other words, the disk 850 can be solid with nofluid communication through the disk in a direction parallel to the axisof rotation (e.g. other than through the central opening), thusprecluding gap-to-gap fluid flow through the disk. At least one disk ina plurality of disks can be solid, and in another option all of theplurality of disks can be solid (exclusive of a central axial opening).

FIGS. 20 and 21 illustrate a turbomachine 800′ in accordance withanother example of the present disclosure. In this case, theturbomachine 800′ includes the turbomachine 800 discussed above withreference to FIGS. 13-16 , which is coupled to one or more generatorsand/or motors 870 a, 870 b. As shown in FIG. 21 , the extension member822 a, 822 b can facilitate coupling the rotor assembly 820 to thegenerator and/or motors 870 a, 870 b. For example, the extension member822 a, 822 b can include a flange 824 a, 824 b to interface with agenerator shaft and/or a motor shaft 872 a, 872 b and facilitatecoupling the rotor assembly 820 to the generators and/or motors 870 a,870 b, such as utilizing fasteners, etc.

In one aspect, the generators and/or motors 870 a, 870 b can beconfigured to cause rotation of the rotor assembly 820, thereby causingmovement of the fluid through the housing 810. The generators and/ormotors 870 a, 870 b can therefore serve to provide torque to theextension member 822 a, 822 b when the turbomachine is operating as apump or to “start-up” the turbomachine when used as a generator. In thelatter case, the generators and/or motors 870 a, 870 b can switch from amotor that provides torque to a generator once the rotor assemblyreaches a desired operating speed. The extension member 822 a, 822 b cantherefore serve as a mechanical transfer coupling for the rotor assembly820 to an external device, such as the generators and/or motors 870 a,870 b. Any suitable generator or motor can be utilized with the boundarylayer turbomachine 800. In one aspect, the housing 810 can be coupled toa housing 871 a, 871 b of the generators and/or motors 870 a, 870 b.

The shafts 872 a, 872 b can include central openings 875 a, 875 b toserve as conduits for fluid exiting or entering the turbomachine 800 viathe extension members 822 a, 822 b. The housing 871 a, 871 b can includeopenings 876 a, 876 b to facilitate the passage of fluid through a wallof the housing 871 a, 871 b. In the illustrated example, the openings876 a, 876 b are in fluid communication with the central openings 875 a,875 b of the shafts 872 s, 872 b, but in some embodiments the shaft canextend through the opening in the housing. Bearings 877 a, 877 b andseals 878 a, 878 b can be associated with the housing 871 a, 871 b tosupport and seal about the shafts 872 s, 872 b.

In one aspect, one or more flywheels 873 a, 873 b can be coupled to therotor assembly 820. The flywheels 873 a, 873 b can be mounted to theshafts 872 a, 872 b and can therefore rotate with the rotor assembly 820about the axis of rotation 801. The shafts 872 a, 872 b can be sized toaccommodate any suitable number of flywheels or other such rotarycomponents. As shown in FIG. 21 , the flywheels 873 a, 873 b can bedisposed within the housing 871 a, 871 b. The flywheels 873 a, 873 b canserve to store rotational energy and/or can include an electricitygeneration member, therefore forming a portion of a generator and/or amotor. The generators and/or motors 870 a, 870 b can also include one ormore stators 874 a, 874 b operable with the flywheels 873 a, 873 b toform a generator and/or a motor. The flywheels can be reduced in size orremoved by making a disk carrier and/or outer disks within the diskassembly having a larger mass.

FIGS. 22A-22F schematically illustrate boundary layer turbomachines inaccordance with several examples of the present disclosure. For example,FIG. 22A illustrates a boundary layer turbomachine 900 configured as apump. In this case, the fluid can enter the turbomachine via openings912 located radially outward from the rotational axis 901, and can moveradially inward to exit the turbomachine via an opening 913 located onor about the rotational axis.

FIG. 22B illustrates a boundary layer turbomachine 1000 configured as avacuum pump. In this case, the fluid can enter the turbomachine viaopenings 1012 located radially outward from the rotational axis, and canmove radially inward to exit the turbomachine via an opening 1013located on or about the rotational axis. This can cause a suction tocreate a vacuum. In one aspect, a check valve 1094 can be associatedwith the outlet to prevent backflow of fluid into an evacuated chamber.

FIG. 22C illustrates a boundary layer turbomachine 1100 configured as afan or a blower. In this case, the fluid can enter the turbomachine viaan opening 1113 located on or about the rotational axis 1101, and canmove radially outward (accelerated) to exit the turbomachine viaopenings 1112 located radially outward from the rotational axis. In oneaspect, a fluid guide structure 1195 can be included to control thedirection of fluid movement upon exiting the turbomachine. For example,a housing of the turbomachine can be configured to control the exitdirection of the fluid.

FIG. 22D illustrates a boundary layer turbomachine 1200 configured as anin-line pump coupled to a fluid conduit 1296. In this case, the fluidcan enter the turbomachine via an opening 1213 located on or about therotational axis 1201, and can move radially outward (accelerated) toexit the turbomachine via openings 1212 located radially outward fromthe rotational axis. In one aspect, a fluid guide structure 1295 can beincluded to cause the fluid to converge back to the smaller diameterfluid conduit. For example, a housing of the turbomachine can beconfigured to funnel or direct the fluid to the conduit.

FIG. 22E illustrates a boundary layer turbomachine 1300 configured as aboat motor. In this case, the fluid can enter the turbomachine via anopening 1313 located on or about the rotational axis 1301, and can moveradially outward to exit the turbomachine via openings 1312 locatedradially outward from the rotational axis for an efficient transfer ofrotational force towards horizontal movement. In one aspect, the fluidcan be directed for vector thrust. For example, the housing 1310 can beconfigured to rotate and/or a nozzle 1397 downstream can be configuredto rotate in order to direct the exiting fluid in one or more degrees offreedom.

FIG. 22F illustrates a boundary layer turbomachine 1400 configured as athruster. In this case, the fluid can enter the turbomachine via anopening 1413 located on or about the rotational axis 1401, and can moveradially outward to exit the turbomachine via openings 1412 locatedradially outward from the rotational axis where the air is compressedfor combustion. Opening 1413 can be configured as with inlet assembly844 described previously in order to transition flow to a rectangularcross-section. The expansion from this combustion can be funneled outthrough a Venturi nozzle 1498 to efficiently create thrust. The boundarylayer turbomachines 1300, 1400 of FIGS. 22E and 21F can be used toprovide power or thrust for any suitable transportation platform, suchas an aircraft, a watercraft (e. g., a boat or a submarine), or aland-based or terrestrial transportation platform.

The direction of fluid flow illustrated in FIGS. 22A-22F representexamples of the fluid flow direction for a given type of boundary layerturbomachine or application. It should be recognized that the directionof fluid flow for a given type of boundary layer turbomachine orapplication may vary from that depicted in the figures.

Furthermore, the apparatus can also be used as a chiller and/or acondenser in refrigeration, HVAC, or engine cooling applications.

FIGS. 23A-23C illustrate drag reducing structures for surfaces exposedto fluid flow, in accordance with several examples of the presentdisclosure. As shown in the figures, ridges with leading edges angled ordirected with the direction of fluid flow can create a vacuum on thetrailing edges as fluid passes over the ridges, forming vortices. Theresult is similar to an air bearing, which can reduce drag over thesurface of the ridges. In one aspect, the ridges can have trailing edgesthat are vertical (1599 in FIG. 23A), undercut (1699 in FIG. 23B),and/or extend away from peaks of the ridges in the direction of flow(1799 in FIG. 23C). The ridges can be of any suitable height. In oneaspect, the ridges are about 0.030 inch in height. The drag reducingstructures can be applied to any surface that is exposed to fluid flow,such as an aerodynamic surface, a vehicle body, a nozzle, etc.

The foregoing detailed description describes the invention withreference to specific exemplary embodiments. However, it will beappreciated that various modifications and changes can be made withoutdeparting from the scope of the present invention as set forth in theappended claims. The detailed description and accompanying drawings areto be regarded as merely illustrative, rather than as restrictive, andall such modifications or changes, if any, are intended to fall withinthe scope of the present invention as described and set forth herein.

What is claimed is:
 1. A boundary layer turbomachine, comprising: ahousing defining an interior space including a rotor chamber, thehousing having an inlet opening and an outlet opening to facilitatemovement of a fluid through the housing; and a rotor assembly disposedin the rotor chamber and configured to rotate about an axis of rotation,the rotor assembly having a plurality of disks spaced apart along theaxis of rotation to provide gaps between the disks, the plurality ofdisks defining an interior opening along the axis of rotation, and adisk carrier comprising a hollow shaft disposed at least partially inthe interior opening in support, of the plurality of disks, the diskcarrier comprising: a fluid passageway formed in the hollow shaft andexposed to two or more of the gaps between the disks, wherein the fluidpasses through the gaps between the disks and the interior opening asthe fluid moves through the housing, and a first extension portion and asecond extension portion of the hollow shaft disposed on respective endsof the disk carrier to couple the rotor assembly to the housing andfacilitate rotation of the rotor assembly about the axis of rotation,and a first vent port and a second vent port in fluid communication withthe interior opening, the first, vent extending through the firstextension portion and the second vent extending through the secondextension portion of the hollow shaft; the boundary layer turbo machinefurther comprising at least one of: a partition circumferentiallydividing the interior space into an outer chamber and the rotor chamberlocated radially inward of the outer chamber, the partition havingpartition openings such that fluid is movable through the partitionbetween the outer chamber and the rotor chamber, wherein the outerchamber is an annular volume having a uniform radial thickness around anentire circumference of the outer chamber; and a plurality of firstouter fluid passageways formed through an outer circumferential surfaceof the first extension portion of the hollow shaft to be in fluidcommunication with the first vent port and a plurality of second outerfluid passageways formed through an outer circumferential surf ace ofthe second extension portion of the hollow shaft to be in fluidcommunication with the second vent port.
 2. The boundary layerturbomachine of claim 1, wherein the fluid passageway comprises aplurality of fluid passageways.
 3. The boundary layer turbomachine ofclaim 2, wherein the plurality of fluid passageways are distributedcircumferentially about the disk carrier and extend along a disk portionof the disk carrier.
 4. The boundary layer turbomachine of claim 1,wherein the disk carrier comprises a disk coupling interface portion,and at least one of the plurality of disks comprises a carrier couplinginterface portion, and wherein the disk coupling interface portion andthe carrier coupling interface portion interface to couple the diskcarrier and the at least one of the plurality of disks to one another.5. The boundary layer turbomachine of claim 4, wherein the disk couplinginterface portion extends radially outward relative to the axis ofrotation.
 6. The boundary layer turbomachine of claim 4, wherein thedisk coupling interface portion and the carrier coupling interfaceportion comprise complementary protrusions circumferentially offset fromone another about the axis of rotation.
 7. The boundary layerturbomachine of claim 4, further comprising a support disk to couplewith and provide support for the plurality of disks, the support diskhaving a second carrier coupling interface portion, wherein the diskcoupling interface portion and the second carrier coupling interfaceportion interface to couple the disk carrier and the support disk to oneanother, wherein the support disk is at least one of: an outer supportdisk configured to be disposed at an end of the plurality of disks, andan inner support disk configured to be disposed between at least two ofthe plurality of disks.
 8. The boundary layer turbomachine of claim 4,wherein the fluid passageway comprises a plurality of fluid passagewaysdefined at least in part by a plurality of spans extending along theaxis of rotation, and wherein the disk coupling interface portion isassociated with the plurality of spans.
 9. The boundary layerturbomachine of claim 8, wherein the plurality of spans extend parallelto the axis of rotation.
 10. The boundary layer turbomachine of claim 8,wherein the disk carrier further comprises a mid-span support coupled tothe plurality of spans and extending circumferentially about the diskcarrier to provide support for the spans.
 11. The boundary layerturbomachine of claim 1, wherein the plurality of disks are orientedperpendicular to the axis of rotation.
 12. The boundary layerturbomachine of claim 1, further comprising a flywheel coupled to therotor assembly.
 13. The boundary layer turbomachine of claim 1, whereinthe inlet opening is associated with the outer chamber such that theouter chamber serves as an expansion chamber for the fluid.
 14. Theboundary layer turbomachine of claim 13, wherein a cross-section of theouter chamber is uniform 360 degrees about the axis of rotation.
 15. Theboundary layer turbomachine of claim 1, wherein at least one of theplurality of disks is a solid disk with no fluid communication throughthe at least one disk in a direction parallel to the axis of rotation,other than through the central opening.
 16. The boundary layerturbomachine of claim 1, wherein the plurality of first outer fluidpassageways and the plurality of second fluid passageways are configuredallow fluid to pass between an interior and an exterior of the diskcarrier.
 17. The boundary layer turbomachine of claim 1, wherein theplurality of first outer fluid passageways are distributedcircumferentially about the outer circumferential surface at the firstextension portion, and wherein the plurality of second outer fluidpassageways are distributed circumferentially about the outercircumferential surface at the second extension portion.
 18. Theboundary layer turbomachine of claim 17, wherein the plurality of firstouter fluid passageways and the plurality of second outer fluidpassageways are respectively formed through the circumferential surfaceat portions of the first extension portion and the second extensionportion disposed outside of the housing.
 19. A rotor assembly for aboundary layer turbomachine, comprising: a plurality of disks spacedapart along an axis of rotation to provide gaps between the disks, theplurality of disks defining an interior opening along the axis ofrotation; a disk carrier comprising a hollow shaft disposed at leastpartially in the interior opening in support of the plurality of disks,the disk carrier comprising: a fluid passageway formed in the hollowshaft and exposed to at least two of the gaps between the disks, suchthat fluid passes through the at least two of the gaps between the disksand the interior opening as the fluid moves through the rotor assembly,and a first extension portion and a second extension portion of thehollow shaft disposed on respective ends of the disk carrier tofacilitate rotation of the rotor assembly about the axis of rotation,and a first vent port and a second vent port in fluid communication withthe interior opening, the first vent extending through the firstextension portion and the second vent extending through the secondextension portion of the hollow shaft; and a plurality of first outerfluid passageways formed through an outer circumferential surface of thefirst extension portion of the hollow shaft to be in fluid communicationwith the first vent port and a plurality of second outer fluidpassageways formed through an outer circumferential surface of thesecond extension portion of the hollow shaft to be in fluidcommunication with the second vent port.
 20. The rotor assembly of claim19, wherein the fluid passageway comprises a plurality of fluidpassageways, and wherein the plurality of disks are orientedperpendicular to the axis of rotation.
 21. The rotor assembly of claim20, wherein the plurality of fluid passageways are distributedcircumferentially about the disk carrier.
 22. The rotor assembly ofclaim 19, wherein the first extension portion and the second extensionportion couple the rotor assembly to portions of the turbomachine. 23.The rotor assembly of claim 19, wherein at least one of the plurality ofdisks is a solid disk with no fluid communication through the at leastone disk in a direction parallel to the axis of rotation, other thanthrough the central opening.